Wire-looping machines



1962 H. SCHMIDT 3,056,089

WIRE-LOOPING MACHINES Filed Feb. 27, 1958 4 Sheets-Sheet 1 I0 I i 34 6 9 7:

Inventor: h''l/VR/CH scum/0r A TTORA/'YS Aug. 21, 1962 H. SCHMIDT 3,050,089

WIRE-LOOPING MACHINES Fil ed Feb. 27, 1958 4 Sheets-Sheet 2 FlG.2a

Heinrich Schmidt INVENTOR.

BY Madam, 7205s 8 flesfiam Aug. 21, 1962 H. SCHMIDT WIRE-LOOPING MACHINES 4 Sheets-Sheet 3 Filed Feb. 27, 1958 jrri enon' HEINRICH SCI-[MID T M a A TI'OR VEI'S Aug. 21, 1962 H. SCHMIDT WIRE-LOOPING MACHINES Filed Feb. 27, 1958 4 Sheets-Sheet 4 MN mm INVENTOR.

Heinrich Schmidt 3,050,089 WIRE-LOOPWG MACHINES Heinrich Schmidt, Dusseldorf, Germany, assiguor to Hein,

Lehmann & Co. Aktiengesellschaft, Dusseldorf, Germany Filed Feb. 27, 1958, Ser. No. 718,018 8 Claims. (Cl. 140-102) This invention relates to a machine for making looped wires, for example sieve wires, which are provided with loops at regular intervals. Usually such machines consist of a drum which is rotatable about a horizontal axis and which contains a supply of wire. The drum can also be turned about a vertical axis and, during its intermittent turning movement, winds the wire about a pin arranged below it, so as to form loops in the wire. The machine further comprises a feed device which unwinds the wire step by step from the drum and delivers it to a straightening and pressing device by which the wire and its loops are straightened, smoothed and/ or pressed.

With machines of the above kind, it is diflicult accurately to regulate the feed of the wire with respect to the periodic looping process, namely, in such a way that the operation proceeds at maximum speed without impairing the formation of the loops. In this connection, the fact that, owing to the wire being unwound from the drum, the moment of inertia of the wire drum continuously alters is of particular importance and leads, in the case of many of the known machines, to irregularities in manufacture. A further disadvantage of the known machines is that the feed of the wire is effected by mechanical means, and, owing to the fixed mechanical coupling between the feed device and the straightening and pressing means which is arranged after it, difficulties occur in the arrangement of the tools.

Further, on restarting the machine or the straightening and pressing mechanism after a stoppage, the mechanical feed device moves at a relatively great speed. This leads, when the speed of working is high, to difierences in pitch, that is to say to the individual loops being at dilferent distances apart.

The object of the present invention is to provide an improved machine which does not possess the abovementioned disadvantage and is also of simple construction and enables the feed of the wire to be accurately adjusted to the movement necessary for the manufacture of the loops. This result is obtained, in accordance with the invention, in that the periodic turning movement of the wire drum to form a loop is effected by a starwheel drive and the control of the looping pin and of the feed device is efiected by hydraulic means. The star-wheel drive for the wire drum advantageously consists of a star wheel which is fixed to the vertical axis of the drum and has a swallow-tailed part and a continuously rotating driving disc which coacts therewith. The driving disc is provided with driving pins arranged around a part of its periphery and with a locking disc which co-operates with the swallow-tailed part. In this way the periodic turning movement of the wire drum is positively controlled entirely independently of the moment of inertia of the drum at any time, because its torque is released or braked and accurately fixed in the correct working rhythm by the locking disc which rotates with the driving disc and by the swallow-tailed part of the star wheel.

The control of the hydraulically operated feed device is eifected by a cam which rotates synchronously withthe driving disc and which adjusts a controlling piston. by means of a control rod or the like. The controlling piston controls, according to its position, the supplyof oil under pressure to working cylinders which operate the looping 3,050,089 Patented Aug. 21, 1962 ice pin and the feed device. In this Way the feed of the wire can be accurately adjusted to the looping movement. In particular, it is possible to adjust the Working tools of the machine when the feed is ended.

A machine constructed in accordance with the invention is illustrated, by way of example, in the accompanying drawing, in which:

FIG. 1 shows a general elevation of the machine;

FIG. 2a shows a plan view of one position in the rotation of the star wheel;

FIG. 2b shows a plan view of the driving disc and the star Wheel in another position;

FIG. 2c shows a plan of the star wheel drive for the wire drum in still another position or" the star-wheel drive;

FIG. 2:! shows a plan view of still another position of the'star-wheel drive'in which the driving disc runs idle;

FIG. 3 shows details of the machine partly in section, namely the parts which are necessary for the looping process of the feed wire,

FIG. 3a is a schematic representation of the pitch employed in the machine;

FIG. 3b is a schematic representation of the cam action of the machine; and I FIG. 30 is a schematic representation of the operation of the hydraulic cylinders of the machine.

As shown in drawing, the machine consists essentially of a frame A, a mechanism B for forming the loops or eyes, a wire drum 34 and its driving means, a feed device C and a straightening and pressing mechanism D.

On a driving shaft 5 mounted in a part 1 of the machine frame A is a bevel Wheel 6 which drives a shaft 7' through a bevel wheel 7. A driving disc 8 and a cam disc 9 are fixed on the shaft 7'. The driving disc 8 is provided with driving pins 11 arranged around a part of its periphery which intermittently turn a toothed star wheel 10, which is fixed to a vertical spindle 34' on which the wire drum 34 is supported. As shown in FIG. 2 the star wheel is provided with a swallow-tailed part 13- which cooperates with a locking disc 12 provided on the driving disc 8. The disc 12 has extending around a part of its periphery, namely the part corresponding to the arc of the disc 8 on which the driving pins 11 are arranged, a recess 12 into which the swallow-tailed part 13 ofthe star wheel 10 can enter as soon as the driving pins 11 engage the corresponding tooth gaps of the Wheel 10. On the other hand, a locking portion 12" of the disc 12 prevents further rotation of the star wheel 10 as soon as the last driving pin 11 has emerged from. the corresponding tooth gap in the star wheel 10, because the part 13 engages the portion 12 of the disc 12. The driving pins 11 of the disc 8 are so arranged that about a half revolution of the disc 8 effects a complete revolution of the star wheel 10. Afterthis, the star wheel 10 is held in a fixed position by means of its part 13 and the locking disc 12. When this driving means is used suflicient time is availablefor the feed of the wire, so that maximum operating speed can be obtained. Further, since the fixed position of the wire drum 34 is positively determined by the swallow-tailed piece 13 of the star wheel 10 and the locking disc 12, it is independent of the amount of wire on the drum 34, that is to say it is independent of the moment of inertia of the drum.

The straightening and pressing tools 2, as well as the further pressing tool 4 of the press D are also driven from the shaft 5 by means of eccentrics. By means'of these tools, the loops of the Wire 3 are pressed together and the wire is profiled and the pitch is accurately calibrated. Since the transmission ratio of the bevel wheels 6, 7 is 1:1, the loop mechanism B works synchronously with the press D.

The hydraulically operated feed" device C and its method of operation will now be described with reference to FIG. 3. A pump 14 delivers oil under pressure in the manner indicated by the arrows to a control cylinder 15 and to an accumulator 16. The accumulator 16 consists of a cylinder 17 having a piston 18, a piston rod 19 and a pressure spring 26 acting on the piston. The accumulator 16 is constructed in such a way that when the piston 18 is in its uppermost position it opens an outlet 21 which acts as a safety valve. A valve piston 22 in the cylinder 15 is moved up and down by the earn 9 driven from the shaft 5. The cam 9 moves a control rod 23 in such a manner that cylinders 29, 30 and 33 which control the feed means are operated in the correct working rhythm. The cylinder 29 with its piston 28 operates a member 27 which carries a looping pin 26 and a distance pin 24. The cylinder 30, which has a fixed horizontal piston 31, 32, effects the feeding of the wire 3 by means of the pin 25, and the cylinder 33, which, with its piston 33" is fixed to the cylinder 30, controls the feed pin 25.

By the above-mentioned controlling device the result is obtained that at any time the wire 3 is securely held either by the pins 24 and 26 which determine the pitch t or by the feed pin 25. In order to be able to adjust the pitch t, the distance pin 24 is adjustably fitted on the member 27. In their lowered positions the pins 24 and 26 release the Wire for its forward feed which begins with the forward stroke of the cylinder 30. For the accurate adjustment or limitation of the stroke to the desired pitch 1, stops, which are not illustrated, are provided. On the return stroke of the cylinder 30 the feed pin 25 is drawn downwards because the pipe leading to the cylinder 33 is then in communication with the oil under pressure.

The feed of the wire takes place when the drum 34 is stationary about its vertical turning axis during the return stroke of the feed cylinder 30 and proceeds together with the looping. process.

In FIGS. 20 to 2d the star-wheel drive is shown in four different positions. The drive disc 8 is rotated by shaft 7 evenly in clockwise direction. When the first bolt 11 engages the first tooth gap of the star Wheel at portion 13, the star wheel and thus the shaft 34' are accelerated. Owing to the rolling of the eleven bolts 11 the star wheel is then turned by 360 which results in the formation of a loop by the wire. When the bolts 11 are not in engagement with the star wheel 10, the position of the latter is fixed exactly at the swallow-tail part 13 by the locking disc 12, namely by its cylindrical portion 12''. Since the locking disc 12 is firmly connected with the drive disc 8 and also with the shaft 7', the locking and releasing of the star wheel occurs fully automatically. The pot-shaped cam disc 9 is also firmly connected with the drive disc 8. This cam disc actuates the piston 22 in the control valve through the roll 23' and the control valve 15 through the roll 23' and the control rod 23.

In the drawing, a development of the cam disc 9 (FIG. 3b) and the several positions of the control piston 22 of valve 15 (FIG. 3c) are shown in all six operating positions. In the highest position A of the control piston the pipes 3', 2' and 1 are placed under oil pressure. Thus piston 28 is in its lowest position and piston 33' is in its highest position. Therefore the looping pin 26 and the distance pin 24 have released the two last loops of the wire 3, while the feed pin engages thethird loop from the end. The pressure oil flowing through the pipe 1' pushes the cylinder towards the right along the piston rod 32. The wire 3 is thereby pulled further to the right (as viewed in FIG. 3) by a pitch t. The corresponding amount of wire is withdrawn from the supply on drum 34 as this drum rotates about its axis. The desired pitch t can be set at the piston rod 32 by means of the ring 32'.

In the position B of control piston 22, the pipes 3' and 4' are under oil pressure. The pressure oil flowing through the pipe 4' moves the piston 28 towards the top, while the distance pin 24 receives the last-formed loop.

The cam disc 9 is secured to the drive disc 8 of the star-wheel drive in such a manner that in this position B the rotation of the wire drum 34 and therefore the formation of a new loop around the looping pin 26 begins.

During the formation of the loop the control piston 22 is moved into the position C in which the pressure oil traverses the conduits 5 and forces the feed pin 25 downward out of the formed loop.

In position D the return of the cylinder 30 into its starting position is effected by the flow of the pressure oil through the pipe 6' and the hollow piston rod 32 into the cylinder 30.

When the looping process is terminated (FIG. 20), the control piston 22 is lifted into position E, identical with position C, in which the pressure oil gets under the piston 33 through the pipe 3' and pushes the feed pin 25 into the third loop from the end.

In the following position F (identical with position B) of the control piston 22, the pipe 2 is connected to the source 14 of pressure oil. Thus the pins 24 and 26 are pulled out of the two last loops by the piston 28 in order to release the wire 3 for further advance.

In the position A the operation cycle begins anew.

The control positions of the piston 22 from A to D occur shortly one after the other. Then the control piston remains in this position D for a longer period in order to guarantee sufficient time for the return of the feed cylinder 30. This time is also available because the formation of a new loop through the rotation of the star wheel 10 occurs only during approximately half a rotation of the drive disc 8. During the other half of the rotation of the dIlVC disc 8 the wire 3 is transported further by a pitch 1. In order to have enough time available also in this instance, the movements of the control piston 22 from position D over the positions E and F into the starting position D- occur again shortly one after the other. In FIGS. 2a, 2b and 2d the angular positions of shaft 34' for the individual switching steps of the cam disc 9 are given.

In order to be able to measure the profile shape of the finished pressed wire or in order to exchange or adjust the tool 2 (FIG. 1), the entire machine has to be stopped. This occurs in the upper dead center of the eccentric press A.

In this position, only half the time available for the transportation has passed. When the press is stopped, the control piston 22 remains in position D. Therefore transportation can take place without disturbance to the end position. If the advance were effected by mechanical means, e.g. a crank drive, a cam disc or the like, the advance would be interrupted by the stopping of the eccentric press. When the eccentric press is started again, the interrupted advance would be continued, with comparatively high acceleration, which would cause undesirable strong drawing forces on the already formed wire. The two finished loops would thus easily be pulled together, i.e. narrowed, the pitch would increase and the wire with its loops would no longer lie in the correct position with relation to the pins 35 of the pressing tool 2 (FIG. 1). Since in all cases the hydraulic means assure an even advance of the wire to the end, they are particularly advantageous for this purpose.

The oil flow coming from the oil pump 14 is periodically distributed by the control piston 22 to the cylinders 29, 30 and 33. This causes the amount of oil to vary strongly temporarily. It would be uneconomical to measure the output of pump '14 according to the maximum amount of oil required. It is enough if the pump delivers the maximum amount of oil required per cycle of operations. If no oil is needed on the working cylinders between the individual operations, the pressure oil is stored in the accumulator 16. FIG. 3 shows as an example an accumulator weighted down by spring pressure. The spring 20 presses upon the piston 18 which is sealed and movable in the cylinder 17. The excess oil lifts the piston 18 against the spring pressure. If, during longer stoppage of the machine or when the pitch 1 is small, an inordinate rise in oil pressure occurs, the piston 18 takes its highest position, thus uncovering the bore 21, so that excess pressure oil reaches the oil container through the outlet 21. A further advantage of the oil accumulator lies in that because of it there is always a practically constant oil pressure available at the control piston 22. The pressure varies only to a small degree according to the more or less strong tension of the spring 20 in the accumulator at varying levels of the piston 18.

The desired pitch 2 must not be set only between the feed cylinder 30 and the ring 32', but also between the looping pin 26 and the distance pin 24.

The looping pin 26 is always located in the extension of the spindle 34 (FIG. 3) underneath the drum 34. The member 27, which is moved up and down over the piston 28, carries a longitudinal bore for receiving the distance pin 24. In FIG. 3a there is shown an outline of the member 27 with this longitudinal bore 27.

When the eccentric press is in its upper dead-center position which corresponds to the normal stationary position for introducing and removing the tools and so forth, the valve piston 22 is in its uppermost positionr In this position the pipes 1, 2' and 3' are under pressure. Since the valve piston remains in its uppermost position when the eccentric press is stationary, the cylinder 30 and, therefore, also the feed pin 25 are brought, in this case, into their outermost feed position. It is, therefore, possible to bring the tool 2 into the correct position, so that the feeding pin 25 can be introduced into the wire loop without trouble on exerting the pressure. As compared with this, in machines with mechanical wire feed, only half the feed takes place in the upper dead-center position of the eccentric press. Since, owing to the mechanical connection of the feeding device to the press, the feed momentarily ceases when the press is stationary, considerable difiiculties occur in arranging the tools as compared with the machine of the present invention.

I claim:

1. A machine for forming a succession of equispaced closed loops on a wire, comprising a support, a spindle on said support having means for holding a supply reel for a wire to be looped, a first pin, a second pin and a third pin spacedly positioned parallel to one another along a path for said wire transverse to the axis of said spindle, said first pin being coaxial with said spindle, said second pin being disposed between said first and third pins at a predetermined distance from said axis, first holder means for said first and second pins displaceable in axial direction of said spindle between one position in which said first and second pins traverse said path and another position in which said first and second pins are withdrawn from said path, second holder means for said third pin displaceable in axial direction of said spindle between one position in which said third pin traverses said path and another position in which said third pin is withdrawn from said path, a carrier connected with said second holder means and reciprocable along said path together with said third pin, drive means for rotating said spindle about its axis, and control means coupled with said drive means, said first and second holder means and said carrier for performing in timed relationship the following operations:

(1) actuation of said drive means for rotating said spindle with said supply reel thereon through a full turn with said first holder means in said one position thereof whereby a loop of wire is formed around said first pin, said second pin concurrently engaging a second loop previously formed in said wire;

(2) displacement of said second holder means into said one position thereof for introducing said third pin into a third loop formed in said wire before said second loop;

(3) displacement of said first holder means into said other position thereof for withdrawing said first and second pins from their respective loops;

(4) advancement of said carrier in a direction away from said axis with entrainment of said wire by said third pin over a distance sufiicient to align said second pin with a loop formed earlier in said wire;

(5) displacement of said first holder means into said one position thereof for inserting said second pin into the loop aligned therewith;

(6) displacement of said second holder means into said other position thereof for withdrawing said third pin from said third loop; and

(7) return of said carrier into a position in which said third pin is aligned with a loop on said wire formed before said third loop.

2. A machine for forming a succession of equispaced closed loops on a wire, comprising a support, a spindle on said support having means for holding a supply reel for a wire to be looped, a first p'in, asecond pin and a third pin spacedly positioned parallel to one another along a path for said wire transverse to the axis of said spindle, said first pin being coaxial with said spindle, said second pin being disposed between said first and third pins at a predetermined distance from said axis, first holder means for said first and second pins displaceable in axial direction of said spindle between one position in which said first and second pins traverse said path and another position in which said first and second pins are withdrawn from said path, second holder means for said third pin displaceable in axial direction of said spindle between one position in which said third pin traverses said path and another position in which said third pin is withdrawn from said path, a carrier connected with said second holder means and reciprocable along said path together with said third pin, continuously operable drive means, coupling means between said drive means and said spindle for entraining the latter with said supply reel thereon through a full turn about its axis to form a loop of wire during a fraction of an operating cycle of said drive means and for maintaining said spindle blocked against rotation during the remainder of said cycle, and timer means controlled by said drive means and coupled with said first and second holder means and said carrier for sequentially performing the following operations in the course of said cycle:

(1) displacement of said first holder means into said one positionthereof in the blocked state of said spindle, thereby introducing said second pin into a second loop previously formed in said wire, said third pin being concurrently maintained by said carrier at a location relatively remote from said axis with said second holder means in said one position thereof;

(2) displacement of said second holder means into said other position thereof upon beginning rotation of said spindle;

(3) movement of said carrier to a location relatively close to said axis at which said third pin is aligned with a third loop formed in said wire before said second loop;

(4) displacement of said second holder means into said one position thereof for introducing said third pin into said third loop;

(5) displacement of said first holder means into said other position thereof upon completion of the rotation of said spindle and formation of a loop around said first pin whereby said first and second pins are withdrawn from their respective loops; and

(6) advancement of said carrier into said relatively remote location with entrainment of said wire by said third pin over adistance sufficient to align said second pin with a loop formed earlier in said wire.

3. A machine for forming a succession of equispaced closed loops on a wire, comprising a support, a spindle on said support having means for holding a supply reel for a 7 wire to be looped, a first pin, a second pin and a third pin spacedly positioned parallel to one another along a path for said wire transverse to the axis of said spindle, said first pin being coaxial with said spindle, said second pin being disposed between said first and third pins at a distance from said axis equal to a predetermined loop spacing, first holder means for said first and second pins displaceable in axial direction of said spindle between one position in which said first and second pins traverse said path and another position in which said first and second pins are withdrawn from said path, second holder means for said third pin displacea'ble in axial direction of said spindle between one position in which said third pin traverses said path and another position in which said third pin is withdrawn from said path, a carrier connected with said second holder means and reciprocable along said path together with said third pin for displacing the latter between a proximal location and a distal location respectively positioned at two and three times said loop spacing from said axis, drive means for rotating said spindle about its axis, and control means coupled with said drive means, said first and second holder means and said carrier for performing in timed relationship the following operations:

:(1) actuation of said drive means for rotating said spindle with said supply reel thereon through a full turn with said first holder means in said one position thereof whereby a first loop of wire is formed around said first pin, said second pin concurrently engaging a second loop previously formed in said wire;

(2) displacement of said second holder means into said one position thereof for introducing said third pin at said proximal location into a third loop formed in said wire before said second loop;

*(3) displacement of said first holder means, into said other position thereof for withdrawing said first and second pins from their respective loops;

(4) advancement of said carrier in a direction away from said axis with entrainment of said Wireby said third pin for bringing the latter into said distal location and aligning said second pin with said first loop;

(5) displacement of said first holder means into said one position thereof for inserting said second pin into said first loop; a

(6) displacement of said second holder means into said other position thereof for withdrawing said third pin from said third loop; and

( 7) return of said carrier into a position in which said third pin is at said proximal location aligned with said second loop for subsequent introduction thereinto.

4. A machine for forming a succession of equispaced closed loops on a wire, comprising a support, a spindle on said support having means for holding a supply reel for a wire to be looped, a first pin, a second pin and a third pin spacedly positioned parallel to one another along a path for said wire transverse to the axis of said spindle, said first pin being coaxial with said spindle, said second pin being disposed between said first and third pins at a distance from said axis equal to a predetermined loop spacing, first holder means for said first and second pins displaceable in axial direction of said spindle between one position in which said first and second pins traverse said path and another position in which said first and second pins are withdrawn from said path, second holder means for said third pin displaceable in axial direction of said spindle between one position in which said third pin traverses said path and another position in which said third pin is withdrawn from said path, a carrier connected with said second holder means and reciprocable along said path together with said third pin for displacing the latter between a proximal location and a distal location respectively positioned at two and three times said loop spacing from said axis, continuously operable drive means, coupling means between said drive means and said spindle for entraining the latter with said supply reel thereon through a full turn about its axis to form a first loop of wire during a fraction of an operating cycle of said drive means and for maintaining said spindle blocked against rotation during the remainder of said cycle, and timer means controlled by said drive means and coupled with said first and second holder means and said carrier for sequentially performing the following operations in the course of said cycle:

(1) displacement of said first holder means into said one position thereof in the blocked state of said spindle, thereby introducing said second pin into a second loop previously formed in said wire, said third pin being concurrently maintained by said carrier at said distal location with said second holder means in said one position thereof;

(2) displacement of said second holder means into said other position thereof upon beginning rotation of said spindle;

(3) movement of said carrier to said proximal location at which said third pin is aligned with a third loop formed in said wire just before said second loop;

(4) displacement of said second holder means into said one position thereof for introducing said third pin into said third loop;

(5) displacement of said first holder means into said other position thereof upon completion of the rotation of said spindle and formation of said first loop around said first pin whereby said first and second pins are withdrawn from their respective loops; and

(6) advancement of said carrier into said distal location with entrainment of said wire by said third pin over a distance sufficient to align said second pin with said first loop.

5. A machine according to claim 4 wherein saidspindle has an end provided with an axial recess facing said first pin, said first pin being received in said recess in said one position of said first holder means.

6. A machine according to claim 5 wherein said spindle is adapted to have said supply reel mounted thereon with its axis transverse to that of said spindle, further comprising guide means for said wire carried on said spindle adjacent said one end thereof at a location diametrically opposite said second and third pins.

7. A machine according to claim 4 wherein said drive means comprises a rotatable shaft, said timer means comprising cam means on said shaft and hydralulic valve means actuatable by said cam means.

8. A machine according to claim 7 wherein said couping means comprises a rotatable disc positively connected with said shaft for rotation therewith, a set of studs peripherally spaced on said disc over a portion of its circumference, a star Wheel positively connected with said spindle and juxtaposed with said disc for rotation by said studs upon motion of said portion past said star wheel, and co-operating formations on said disc and said star wheel for holding the latter stationary during motion of the remainder of said circumference past said star wheel.

References Gited in the file of this patent UNITED STATES PATENTS 468,301 Cooper Feb. 2, 1892 1,118,019 Kitchen Nov. 24, 1914 1,407,184 Booth Feb. 21, 1922 2,713,175 Fray July 19, 1955 err: Aim 

